Figure 3. IL-15 drives STAT3 activation in non-malignant but not in malignant T cells (A) Non-malignant (MySi) and malignant (MF2000) T cells were cultured with or without IL-15 neutralizing antibody (IL-15 Ab, 2 μg/mL) for 30 min. Then, IL-15 (10 ng/mL) was added as given and the cells cultured for 30 min or 4 h further. Finally, the cells were lysed and the lysates analyzed by western blotting using antibodies against pYStat3, Stat3, and Erk1/2. (B) Malignant T cells (MF2000) were cultured with and without IL-15 Ab (2 μg/mL) for 30 min, 4 h, or 24 h. Subsequently RNA was purified from the cells and reverse transcribed to cDNA that was subjected to quantitative PCR analysis to determine the relative level of IL-17F and GAPDH mRNA. In each sample, the level of IL-17F mRNA was normalized to that of GAPDH mRNA and depicted as fold change when compared with cells cultured without IL-15Ab for the same period of time.